Process of recovering metals from their sulfid ores.



No. 885,761. PATENTE-D APR; 28, 1908.

' E.F.KBRN. PROCESS OF REGOVERING METALS FROM THEIR sumo ORES.

APPLICATION FILED SEPT. 1, 1906. V

Witnesses. Inventor:

' EDWARD FRANK KERN, or KNOXVILLE, TENNESSEE;

PROCESS OF REGOVERING METALS FROM THEIR $ULFID ORES.

Specification of Letters Patent.

Patented April 28, 1908;.

Application filed September 1, 1906. Serial no. 333,018.

To all whom it may concern: i

Be it known that LEDWARD FRANK KERN, a citizen of the United States, residing at Knoxville, county of Knox, and State of Ten nessee, have invented certain new and useful Improvements in Processes of Recovering Metals from their Sulfid, Ores, of "which the following is a specification, accompanied by drawing.

My invention relates to processes for the electrolytic recovery vof metals from their the ore, the lead and associated metals of the .ore may be deposited at, or in, the cathode,

while the sulfur, with which the metals are combined, is liberatedfrom the bath, rovided the temperature be above the :bo1 ing point of sulfur, which is 445 C. Fre uently the naturally occurring galenais toone, be-

ing in'the form of concentrates, or is associated with too much gangue material, to be directly suitable for the electrol sis; so I accordin ly first melt the ore un er a suitable flux, t us collecting its metal content as a fused matte, which-may be cast into suitable blocks or cylinders, and a slag, which con-' Such tains most of the 'gangue material.

0 cast ore or matte, being blocks or cylinders 'good conductors of electricity, are made the I anodes, and also serve-the purpose of carrying the current from an exterior conductor to the working surface of the anode. 1 The cast matte consists practically of the sulfids of lead, zinc, copper, iron, etc., and carries the gold, silver and other values of the ore.

As electrolytes, I prefer to use baths, containing lead chlorid. Fused lead ohlorid has considerable dissolving power for lead sulfid, so the bath-is nearly oruite saturated with lead sulfid, giving an eectrolyte which is fluid at 500 C.

Other salts may be mixed with the lead chlorid, for example the haloid salts of the alkalies and alkaline-earths, and zinc chlorid. I am' not restricted to the use of chloride volts.

for the electrolyte, as the process will evidently succeed also with, for example, the fluorids, and mixtures of haloid salts with alkali hydroxids: the main object being to secure a bath which will melt at the proper temperature, not be too'volatile, and conduct the current well. 4

. Regarding the use of mixtures of salts, I have used :-2 parts NaOl 1 part CaQl,+ 1 part PbCl and 1 part NaCl 2 artsCaCl 1 part PbCl,; and 3 parts Na 1+ 1 part PbCl,. In all casesth'e mixtures were saturated, in their molten condition, with lead sulfid. These mixtures were fluid between 500 C. and 650 0.

The electrolysis, and the results, are similar with difierent suitable baths, or electrolytes; the main diflerence resulting from the dlfferent'temperatures of worki upon the melting point oft e bath, or electrolyte, used. It is necessarythat the meltingpolnt of the bath, or electrolyte, be below that of the sulfid era, in order that the anode remains Solid-1 It is advanta cons to use a bath, or

electrolyte, which wi melt and remain fluid in the region of 500 (3., as a savlng 1n the cost'of keeping it molten 'is thus effected.

bath having a melting point below 450 0.

would be no great advantage, as a temperature ofat least 50 above the boilin pomtof sulfur, which is 445 0., should e maintained in order 'to' effect the ra id removal of the sulfur from the cell by v0 atilization.

The electric current efiiciency, I have found in a number of experiments, to vary from 88% to 94 the electromotive-force usually being about 2.5. volts with an anode current density of about 500 amper es per s uare foot. With a current density of a out 1200 amperes per square foot, the electromotiv'e-force varied from 4.5. to 6.0 In either case, the distance from anode tocathode was from 1% to 3 inches.

The lead which was reduced at the cathode I was malleable, and free from sulfur, at least for all practical purposes, and the sulfur liberated at the anode was free from chlorm and sulfur chlorids. I

I am enabled .by my process to also recover the zinc occurring in lead ores, The zinc accumulates in the electrolyte, from which it maybe recovered by anysuitable 0 method. Having reference. to the a'ccompanym drawing, I have shown a view in vertic-a pound, with sai cross-section of an apparatus in which I may carry out my invention. The a aratus consists of an iron vessel B, its insi e walls lined with a refractory and non-conducting material D. This constitutes the electrolyzing cell, which contains the fused electrolyte E. The ore, or sulfid containing material, made into suitable form for electrolysis by fusing with a flux and the resulting matte cast into blocks or a c linder A, is placed in the electrolyte E, and brought into electrical contact with the source of the current. The cathode C, is a bath of molten metal in the bottom of the cell B, which is in electrical contact with the source of the current. The molten metal cathode C, is maintained at a constant height by having a well G on the side of cell B, and as ra idly as the metal accumulates, it may be eit er ladled out or else tapped from the apparatus. In order to recover the sulfur which is liberated at the anode during electrolysis, the apparatus maybe provided with a cover H of refractory material, and the volatilized sulfur, or its oxidized products, such as S0,, removed from the cell through the opening J.

The apparatus may be arranged above a suitable furnace F for the purpose of fusing the metal-cathode andthe electrolyte, preparatory to the electrolysis, and for keeping the temperature constant during the operation.

What I claim as new and desire to secure by Letters Patent, is: K

1, The process of recovering lead and associated metals from lead sulfid-containing ore which consists in treating the same to increase its electrical conductivity and then electrolyzing a suitable fused electrolyte comprising a metal haloid compound, with said treated material as anode.

2. The process of recovering lead and associated metals from lead sulfid-containing ore which consists in treating the same to increase its conductivity and then electrolyzing a suitable fused electrolyte comprisin a metal haloid compound and a metal sul d, with said treated material as anode.

3. The process of recovering lead and associated metals from lead sulfid-containing ore which consists in fusing the same to remove impurities and increase its electrical conduct1v1ty, and in electrolyzing a suitable fusedelectrolyte com rising a metal haloid comd fused sulfid-containing material as anode.

4. The process of recovering lead and associated metals from lead sulfid-containing ore which consists in fusing the same to form a matte and then electrolyzing a suitable fused electrolyte comprisin a metal haloid compound and metal sul d, with-said matte as anode.

5. The process of recovering lead and associated metals'from lead sulfid-containin'g ore which consists in fusing the same to form a matte and then electrolyzing a suitable fused electrolyte comprising lead chlorid, with said. matte as anode.

6. The process of recovering lead and associated metals from lead sulfid-containing ore which consists in fusing the same to form a matte and then in electrolyzing a suitable fused electrolyte comprisin a metal chlorid and a metal sulfid, with sai matte as anode.

7. The process of recovering lead and associated metals from lead sulfid-containing ore which consists in fusing the same to form a matte, and then in electrolyzing a suitable fused electrolyte comprising lead chlorid and lead sulfid, with said matte as anode.

8. The process of recovering lead and associated metals from lead sulfid-containing ore which consists in fusing the same to form a matte, and then in electrolyzing a suitable fused electrolyte com rising haloid compounds of lead and zinc aving a metal sulfid issolved therein, with said matte as anode.

9. The process of recovering lead and associated metals from lead sulfid-containing ore which consists in fusing the same to form a matte, and thenelectrolyzim a suitable fused electrolyte comprising a ha loid metal compound, at a temperature below the melting point of said material and above 445 C., 95 with said matte as anode.

10. The process of recoverin lead and associated metals from lead sul d-containing ore which consists in fusing the same to form a matte, and then electrolyzing a suitable fused electrolyte at a temperature of about '500 0., said electrol te comprising a metal haloid compound wit said matte as anode.

11. A process of recovering lead and associated metals from lead sulfid-containin ore, which consists in first fusing said ore with a suitable flux to form amatte and electrolyzin a suitable fused electrolyte, with the said matte as anode.

1-2. A process of recovering lead and associated metals from lead sulfid-containing ore, which consists in first fusing said ores with a suitable flux to form a matte and electrolyzing a suitable fused electrolyte, comprising a metal haloid compound, at a temperature below'the melting point of the matte, with said matte as anode. I

13. A process of recovering lead and associated metals from lead sulfid-containing ore, which consists in first fusing said ores with a suitable flux to form a matte and electrolyzing a suitable-fused electrolyte, comprising a metal haloid compound, at a temperature above 445 C. and below the melting point of the matte with said matte as anode.

14. A process of recovering lead and associated metals from lead sulfid-containing ore, which consists in first fusing said ores with a suitable flux to form a matte and electrolyzing a suitable fused electrolyte, comprising a 130 ciated metals from lead sulfi haloid compound of lead and-a haloidcompound of an alkali or alkaline earth metal, at a temperature above 445C. and below the meltin point of the-matte, with said matte as ano e. a i

15. A process of recoverin lead and assocont aining ore, which consists in first fusing said ores with a suitable flux ,to form a matte and electrolyzin% a suitablefused electrolgte, com 'rismg ha oid salts of lead, zinc an of an a alior alkaline earth metal, at a temperature above 445 C. and below the melting point of the matte, with said matte as anode.

16. A process of recovering lead and associated metals from lead sulfid-containing ore, which consists in first fusing said ore with a suitable flux to form a matte and electrolyzing a suitable fused electrolyte, comprismg lead chlorid, at a temperature of about 500 0., with said matte as anode.

17. A process of recovering lead and asso- Y ciated metals from lead sulfid-containing ore,

which consists in first fusing said ores with a suitable flux to form a'matte and electrolyzing a suitable fused electrolyte,comprismg lead chlorid, zinc chlorid and an alkali or alkaline earth haloid compound, having zinc sulfid dissolved therein, at a temperature ,of about 500 0., with said matte as anode.

In testimony whereof, I hereunto set my WM. S. Aus'rrn, R. B. SHnRIDAN. 

